Freshwater Ecosystems Lakes, Rivers and Streams Aquatic Ecosystems Freshwater Ecosystems Lakes, Rivers and Streams

Objectives Be able to describe the factors that determine where an organism lives in an aquatic ecosystem Be able to describe the littoral zone and benthic zone that make up a lake or pond Be able to describe 2 environmental functions of wetlands Be able to describe one threat against river ecosystems

Aquatic Ecosystems The types of organisms that live in an aquatic ecosystem is determined by the water’s salinity Salinity is the amount of dissolved salts the water contains. Freshwater= <0.5 ppt Saltwater= 30-50 ppt Aquatic Ecosystems are divided into Freshwater and Saltwater or Marine

Freshwater vs Saltwater Lakes and Ponds-Slow Rivers and Streams-Fast Wetlands-water logged land Marshes and Swamps Saltwater or Marine Marshes and Swamps-Coastal Coral Reefs Deep Oceans

Characteristics of Aquatic Ecosystems Aquatic Ecosystems are characterized by Temperature Sunlight Depth Oxygen Concentration Available Nutrients Aquatic Organisms are grouped by their location at water depths and adaptations Plankton-Surface, provide most of food, producers Zooplankton-microscopic animals Phytoplankton-microscopic plants Nekton-Free swimming organisms Fish, Turtles, Whales Benthos-Bottom dwelling organism, lived attached to hard surfaces Mussles, worms and Barnacles

Lakes and Ponds Form naturally where ground water reaches the Earth’s surface Humans and animals like beavers create lakes and ponds by interrupting water flow Lake structure-2 zones Littoral Zone-Surface, Sunlight Aquatic Plants and Animal Benthic Zone-Bottom, Dark Bacteria, Decomposers, Bottom Feeding Fish Animal Adaptations-Whiskers on Catfish to find food on the bottom, Amphibians burrow into the mud in winter to avoid freezing

Nutrients in Lakes Lakes with an abundant amount of nutrients, causing overgrowth of plants, algae and bacteria are known as Eutrophic Lakes Depletion of oxygen in these lakes called Eutrophication-kills off oxygen requiring organisms Rainwater runoff carrying sewage, fertilizers and animal wastes from land into the water accelerates Eutrophication

Wetlands Areas of land covered by water for part of the year 2 Types of Wetlands Marshes-contain nonwoody plants such as cattails, low, flat lands, characterized by salinity-ex. Florida Everglades Swamps-dominated by woody plants such as cypress trees, low, poorly drained land, good habitat for amphibians- ex. Louisiana bayou 2 Purposes of Wetlands Filter and absorb water-prevents pollutants from entering ground water Control Flooding-absorb river overflow Homes and nesting area for migratory birds Cranberry, crawfish production Wetlands are protected in many states

Rivers Originate from snow melt in the mountains of Minnesota 1475 ft above sea level 2320 miles long, flows southward in meanders, terminating 95 miles below New Orleans at sea level or O ft. 4th longest river in the world Changes with the land and climate through which it travels Higher altitudes-cold, narrow, fast, oxygen rich-Head Waters Trout, Minnows, Moss Lower altitudes-warmer, wider, slower and decreased dissolved oxygen-Ends in a fan shape called the Delta Plankton, Carp, Catfish Arrowhead, Crowfoot

Threats to River Systems Industries use river water in manufacturing processes and release waste into the waters. People dispose of sewage and garbage in rivers Pollutants and toxins produced have killed river organisms and made river fish inedible Water runoff from land carries pesticides, fertilizers and manufacturing chemicals into the river coating sediment with toxic waste Pollutants enter ground water and human drinking water resources in rural areas.

What Do You Know?-60 points 1.Why are aquatic ecosystems divided into freshwater and saltwater? 2. Freshwater ecosystems include what 7 bodies of water? 3. Summarize the 4 factors that characterize where organisms live in aquatic ecosystems? 4. Compare the littoral zone and benthic zone of lakes. 5. Describe 2 environmental functions of wetlands. Trace the path of the Mississippi river, where does it start and end? 6. Discuss the importance of one threat against river ecosystems Answer the questions and complete the tasks above. All of the answers can be found in the PowerPoint presentation Write the questions. Answer each question using complete sentences.

Black History Month Extra Credit 110 points Who founded the first settlement of Chicago? When was this person born? Where was he born? Who were his parents? Who did he marry? What were the names of his children? Name the river upon which the settlement was founded. What was his occupation? When did he die? Where is he buried? What Chicago Public School and Museum is named after this person?